This invention relates to an apparatus for applying fluidic material, and more specifically to an apparatus for applying a predetermined quantity of fluidic material.
In industrial manufacturing plants a great many repetitive assembly operations require the application of fluidic material such as grease, adhesive, sealants, and other relatively high density and high viscosity material. These operations usually require a relatively small volume shot of material, but it is important that such material be repeatably dispensed, frequently in places which are difficult of access. Cost efficiency in manufacturing operations also requires that excess material applications be kept under strict control, and the quality of the manufacturing process requires that materials be uniformly and consistently applied with highly accurate repeatability so that product quality can be kept uniform.
For example, an automobile manufacturing plant has hundreds of assembly operations which require the application of glue or RTV silicones on parts to hold them together. Small quantities of grease and other lubricants are required to be applied to areas where moving parts contact one another, and sealers, sound deadening insulation, and adhesives are used in considerable quantity. Each of these many fluidic materials are applied to the product as it moves down an assembly line in sequential and repeatable fashion. The cost and quality of the final product is determined in part by the extent to which these material applications can be tightly controlled. Material applications such as described above are typically metered in the 0-2 fluid ounce range by a hand-held gun applicator device. Because a great number of such operations may be performed in any given time period, it is desirable that the gun triggering mechanism be actuated with minimal force. Since the fluidic materials dispensed by such apparatus are usually of high viscosity, a pneumatic piston valve is usually used in conjunction with the trigger to provide an assist to the trigger valving force necessary for opening and closing the fluidic material valve. The fluidic material is typically delivered to the applicator gun in a pressurized hose, and the pressurized air supply used to operate the gun triggering mechanism is delivered in a second pressurized hose. The trigger mechanism opens an air valve which actuates an air piston assembly connected to the fluidic material valve. This opens the fluidic material valve and enables the pressurized fluidic material to pass through the applicator gun and onto the product part. When the trigger is released, the air supply to the air actuated piston is removed and a return spring generally closes the air piston and fluidic material actuator valve. The flow of fluidic material through the applicator gun then ceases.